This invention relates to a filter device and in particular to a self-cleaning filter device that is adapted for use on a faucet, particularly a kitchen sink faucet where water is used for cooking and drinking.
The self-cleaning filter device is incorporated into modern faucets by replacing the threaded end orifice or aerator with the modular self-cleaning filter device. The filter device includes a screen-type filter or a porous-type filter commonly made of a ceramic or metal material.
In a conventional filter device, particulate matter is trapped in the surface of the filter unit. The particulate matter either remains on the surface where it accumulates affecting the efficiency of the filter unit to pass water or more disturbing, eventually dissolves and passes as dissolved matter or reduced-size particulate matter. Worse, accumulated particulate matter can provide a bed for propagation of bacteria, mold or other deleterious microbes. Ideally, it would be beneficial to flush the surface of the filter unit after each passage of water. In this manner particulate matter will not accumulate and adversely affect the performance of the filter unit as described above.
It is therefore an object of this invention to provide a filter device that is self-cleaning to prevent the accumulation of particulate matter deposited on the filtering element. Additionally, it is an object of this invention that the self-cleaning filter device operate automatically, and at least one before or after water passes through the filter device.
In accordance with this invention, a filter device has been devised that is automatically self-cleaning and provides a flushing action over the surface of the filtering element of the filtering unit both before and after water passes through the unit. The filter device is primarily adapted for use as a water filter for a faucet, but can be adapted for other uses where the flushing fluid is disposable or returnable to a fluid reservoir.